Modulation of the phagosome proteome by interferon-gamma.

Macrophages are immune cells that function in the clearance of infectious particles. This process involves the engulfment of microbes into phagosomes where these particles are lysed and degraded. In the current study, we used a large scale quantitative proteomics approach to analyze the changes in protein abundance induced on phagosomes by interferon-gamma (IFN-gamma), an inflammatory cytokine that activates macrophages. Our analysis identified 167 IFN-gamma-modulated proteins on phagosomes of which more than 90% were up-regulated. The list of phagosomal proteins regulated by IFN-gamma includes proteins expected to alter phagosome maturation, enhance microbe degradation, trigger the macrophage immune response, and promote antigen loading on major histocompatibility complex (MHC) class I molecules. A dynamic analysis of IFN-gamma-sensitive proteins by Western blot indicated that newly formed phagosomes display a delayed proteolytic activity coupled to an increased recruitment of the MHC class I peptide-loading complex. These phagosomal conditions may favor antigen presentation by MHC class I molecules on IFN-gamma-activated macrophages.

The effect of immunization with killed tumor cells, with/without feeding of Echinacea purpurea in an erythroleukemic mouse model.

OBJECTIVE: Tumor amelioration via vaccination/immunization is a practice for which considerable experimental and clinical support is growing. Combination therapies have proven to be more beneficial than treatment with single agents. We hypothesized that immunization of mice with killed erythroleukemia cells prior to the induction of erythroleukemia via injection of viable tumor cells, plus dietary administration of a known immuno-enhancing phytocompound, Echinacea purpurea, would be more effective than immunization alone. DESIGN: A commercially available extract of E. purpurea root, already proven as a natural killer (NK) cell stimulant, was administered via the chow, for periods of 9 days or 3 months after the onset of leukemia to mice which had been injected (immunized) 5 weeks earlier with killed leukemia cells. RESULTS: Immunized mice (+/- E. purpurea) had significantly prolonged life spans versus non-immunized mice, with an even greater proportion of hosts surviving long-term in the E. purpurea-fed group. NK cells, the mediators of nonspecific immunity and well-demonstrated mediators of tumor cytolysis, were very significantly elevated in immunized, leukemic mice receiving E. purpurea in their diet versus those receiving untreated chow. Early in tumor development (9 days), cells mediating specific immunity (T, B lymphocytes) were 10-12 times higher in absolute numbers in the spleens in all immunized, leukemic mice vs unimmunized, leukemic mice at the same stage of tumor progression. CONCLUSIONS: The results demonstrate that combination therapy, involving specific tumor cell immunization, followed by daily phytotherapy (dietary E. purpurea), sensitized the immune cells and led to life span prolongation greater than that provided by immunization alone.

Personalised medicine in Canada: a survey of adoption and practice in oncology, cardiology and family medicine.

Introduction In order to provide baseline data on genetic testing as a key element of personalised medicine (PM), Canadian physicians were surveyed to determine roles, perceptions and experiences in this area. The survey measured attitudes, practice, observed benefits and impacts, and barriers to adoption. Methods A self-administered survey was provided to Canadian oncologists, cardiologists and family physicians and responses were obtained online, by mail or by fax. The survey was designed to be exploratory. Data were compared across specialties and geography. Results The overall response rate was 8.3%. Of the respondents, 43%, 30% and 27% were family physicians, cardiologists and oncologists, respectively. A strong majority of respondents agreed that genetic testing and PM can have a positive impact on their practice; however, only 51% agreed that there is sufficient evidence to order such tests. A low percentage of respondents felt that they were sufficiently informed and confident practicing in this area, although many reported that genetic tests they have ordered have benefited their patients. Half of the respondents agreed that genetic tests that would be useful in their practice are not readily available. A lack of practice guidelines, limited provider knowledge and lack of evidence-based clinical information were cited as the main barriers to practice. Differences across provinces were observed for measures relating to access to testing and the state of practice. Differences across specialties were observed for the state of practice, reported benefits and access to testing. Conclusions Canadian physicians recognise the benefits of genetic testing and PM; however, they lack the education, information and support needed to practice effectively in this area. Variability in practice and access to testing across specialties and across Canada was observed. These results support a need for national strategies and resources to facilitate physician knowledge, training and practice in PM.